Hydraulic control device



Aug- 25, 1959 J. L. GRA'rzMUL-LER 2,900,960

HYDRAULIC `CONTROL DEVICE 'Filed Jan. s, 1955 s sheetssheet 1 LIIII' H.Il F u .M (IIL D: idw?. L

A118 25,4 1959 .1. L. GRATZMULLER 259005960 HYDRAULIC CONTROL DEVICEFiled Jan. s. 1955 3 Sheets-Sheet 3 l rya- United States Patent C Thepresent invention relates to pressure fluid control systems wherebyfluid under pressure is delivered in one direction for producing adesired effect and is discharged in another direction for exhaust orrelease.

In such control systems it is often desirable to reduce the timerequired for control valve operation and it is the main object of thepresent invention to provide an improved larrangement in which thedesired time reducjtion for control -valve operation is obtained in asimple but `eliicient` manner.

It is a further object of the invention `to provide a pushbuttonoperated iluid ow control device to be inserted in the pressure line ofa fluid motor to permit `flow of pressure fluid from a continuous fluidpressure source to one side of said motor while checking its return andto discharge fluid from said motor through said pressure line whilechecking the supply of pressure lluid from the source.

In carrying out the invention, two push button operated control valvesare provided for controlling the i main fluidlilow control device, oneof said pushbutton operated valves being adapted to control the `flow ofpressure fluid from the source to a valve actuating memberof the mainfluid ilow control device responsive to iluid pressure from said sourceand also responsive to fluid pressure from said fluid motor, and theother pushbutton operated valve being adapted to connect said fluidpressure responsive valve Iactuating member of the main ow controldevice with the exhaust, the arrangement being :such that a short manualor remote controlled opening of said one pushbutton operated controlvalve will subject the pressure responsive valve actuating mem- `ber ofthe main How control device to suilicient lluid pressure from the sourceto move said valve actuating member to a position in which said fluidmotor is connected to the source, whereafter the lluid pressureconducted to the uid motor through the main ow control device willmaintain said pressure responsive valve button operated control valvehas been opened to connect the pressure responsive valve actuatingmember to the exhaust to thereby permit the valve actuating member toreturn into a position in which it connects the uid motor with theexhaust.

actuating member in said position until the other push- It is also anobject of the invention to provide a pushi button operated fluid flow.,control device particularly adapted for controlling the operationrof,electric circuit i breakers having an operating piston one side of which`is subjected to therforce of resilient means and the other `side ofwhich may-be subjected to uid` pressure 'adapted to move the pistonagainst the action of said resilient means.

Other objects and advantages of the invention will be apparent from thefollowing detailed description together with the accompanying drawings,submitted for purposes of illustration only and not intended to definethe scope of the invention, reference being had for that purpose to thesubjoined claims.

In these drawings:

Figure l is a general diagrammatical View of a hydraulic control deviceaccording to the invention,

Figure 2 diagrammatically shows such a hydraulic control device in itsapplication to the control of a spring-loaded jack, A

Figure 3 shows the fluid low control device as applied to the control ofa single acting hydraulic jack adapted to operate an electric circuitbreaker.

` Referring to Figure l, there is shown `a hydraulic system adapted todeliver liquid under pressure in one direction for producing a desiredeffect, said system comprising a continuous liquid pressure source,e.g., a hydropneumatic accumulator 1, 1a utilization pressure line 2cleading to a Huid motor (not shown), and a low `pressure tank orreservoir 43.

The flow control device according to the invention `comprises a main owcontrol valve 9 having two movable valve members therein. The body ofthe main valve 9 is formed with two coaxial chambers, one of whichconstitutes a piston chamber and the other a valve chamber 53 providedwith an inlet port connected to the `source 1 by a pipe 2a, an outletport communicating lwith the pressure line 2c, and an exhaust portconnected ,piston 8 slidably mounted in the piston chamber of valve 9 todivide said piston chamber into two compartments 46 and 47 of variablevolume. The compartment 47 continuously communicates with thelowpressure container 43 throughV a duct 45. The compartment 46 may becommunicated through pipes 48, 49, -50 with the source 1, under thecontrol of a normally closed feeding valve 29, the opening of which isdetermined by triggering means diagrammatically shown in Figure l, inthe form of a push-button 6a. The compartment `46 may be alsocommunicated through pipes 48, 51, 52 under the control of a normallyclosed unloading valve 24, e.g. with the low-pressure container 43,through a duct 54, notfully shown in Figure l. The opening of theunloading valve 24 is determined by triggering means diagrammaticallyshown in Fig- `ure 1 under the shape of a push-button 15a. v

lvloreover, pipes 11, 5l, 48 permanently communicate i `the utilizationcircuit 2c with the compartment 450i the` l valve.. 9 and a owlimitingdevice; diagrammatically shown in Figure l in the form of acalibrated-hole35 `isinterposed in the said pipe ll, for the hereunderdescribed purpose.

This ldevice operates as follows:

As soon as the push-button 6a is depressed; the feeding valve 29 isopened and the compartment 46 of the valve 9 is fed with pressureliq'uid from the source 1. Since the eifective area of lthe piston 3 ofthe differential piston assembly is greater than the effective area ofthe valve member 5, both said areas being acted upon by the same liquidpressure, the differential piston assembly is shifted from the unloadingposition to the feeding position. The utilization circuit 2c leading toa hydraulic jack H] is now fed with pressure liquid from the source .1,While piston Zblocks Communication betweenircilit 2c and thelow-pressure container 43.

The vpipe 1i conducts pressure liquid from the i 1 tiliza tioncircuit20, into the compartment '46 gthroughj' the pipes'Sl and' 4S, to`therebyrnaintain, in the said com partment, a liquid pressuresufficiently high to maintain the valve member in feedingposition."'Fromthis moment, i.e. a short time after the feeding valve 29 has beenactuated, this feeding valve may be'olosed again without causinginterruption of the feeding of the utilization circuit. This conditionpersists until the push-button'lSa is depressed, which causes openingofi the unloading valve Z4. The rate of the feeding ow 'of thecompartment 46 from the utilization circuit 2c is limited byithecalibrated hole 35 and it will be easily understoodjthat 'if therelativecalibrations of the said hole` andthe evacualtion outletcontrolled by theunloading valve 2li; is so caloulated that the rate ofdischarge through` the said valve v24 is higher than the rate `offeedingjthrough the said -ealibrated hole, Vthe liquid previouslyContainedin the Vcompartment lio will be evacuated through rthe pipes52,

54. y--ln these conditions,` the piston S being no rnore -acted upon Vbyany pressure, while the Valve member 5 continues to-be-subiected to thepressure of the source 1 in the space 53s, the differential pistonassembly will be reset-into-unloading position, thus setting theutilization circuit-2c into communication with the container 43, whileinterrupting the feedingcornmunication between thelsource i and the saidutilization circuit 2c.

In the embodiment-of `Figure 2, there isshown at l,

-as above, thesource of pressure liquid and at 2a, 2b,

2c, 2d, the feeding duct of a hydraulic jack 3, eg., pro- ,.vided toactuate a circuit-breaker, the following description being made withthis assumption, it being well vunderstood-that the said jack 3 couldcontrolany other mechanism as well; 4 is the piston of said jack; 5 is a8, While designates a spring loading said piston; 6 is a circuit-makingelectro-magnet andis a Vcircuitbreaking electro-magnet.

In this embodiment, the control device according to the inventionensures a rapid evacuation of the liquid from the circuit-making jack 3,in spite of the limited action of the electro-magnet'i since it ispossible to unload the .circuit-making jack 3 through an outlet of asection as -large as desired. Since, on lthe other hand, the ball valve25 requires no 'lost motion before its opening, thevdevice `also ensuresa short time-of response to the circuit-breaking order. Rod 26 betweenthe ball valves 5 andZS ensures, when piston 8 is ysubjected to thel.liquidpressure from source 1 to close the ball valve 25, the openingof ball valve 5 while, conversely, when the piston 8 is `unboth valves 5and Z5 are simultaneously opened.

=1oaded, the springV l() permits both opening of the ball i valve 25 andclosing of the ball valve 5. The feeding rate of flow through .thedeliveryV pipe 2a, 2b is preferably limited by means of a calibratedhole 27, to reduce the the yunwanted building-upV of .liquid pressnrb Q.L piston .8 whenball valve` 25 is in'unloadingpositionzliqnid 54'respectively.

sure'in/the feeding duct 2c `ofthe circuit-making-jaclg 3.

To the main ilow control valve 9 are connected, as in Fig. l, twoindependent feeding ducts; one of the said ducts 28a, 2811, 28e,controlled by a feeding valve 29 adapted to be triggered by thecircuit-making electromagnet 6, ensures the building-up of the initialpressure for closing the valve 25 and opening the valve 5; the otherfeeding duct 11a- Mln ensures automatic sustaining of the said pressure,as long as the piston 8 is not unloaded. In this embodiment, non-returnvalves 30, 3E, the respective loading springs of which are shown at 32and 33, are interposed between the feeding ducts 2gb, 28C and ila, lllbrespectively, of the valve 9, to prevent liquid from counter-ilowingtowards either feeding source. Thonon-return `valvell has vforitspurpose to avoid, as the feeding valve 29 is triggered, any loss of timein the building-up, of the operative pressure below piston 8 whilethenon return valve 30 has the advantage of permitting to use a feedingvalve 29, that may give rise toi slight leakages towards the ylow-pressure. container without prejudice. tro-magnet l5 may be automaticallycontrolled by a device 34 responsive to the pressure in the source 1,e.g., through a hydraulic system and electric circuits, not shown inFigurel. kFurthermorqthe pressure-responsive. devicefSfmayf. also.control a device prohibitingany y energizing of .the circuitmalingelectro-magnet 6, when the .pressure inthe ysource i. is insufficientfor thepurposes aimed at.

It will be ,easily understood that,v if the piston 8 is ,to be rapidlyunloaded, as thecircuit breaking order., iswre- `ceiired` itisindispensable, that the feeding ofnithe said vided fan evacuationoutlet controlled Vby aiylvalvepwS which is closed as valve 29 isopened, duedtonthe interpositionbetween both valvesof a pushing rod39.

. arrangement .haSifOrstS; purpose 10 V.Permit ,owilsaithe liquidcontainer 43 of lealtages between the valve 9iand its seat, if any/,suchleakages risking, otherwise,-,to ause fiowsthroughpipe 54 tocontainer43,and duts55 56 provideI communication between i the chambermcontaining valve 38, the chamber containing valve `Z4 andpipe .Thereisdiasrammaticallrhswn atall assess@ pressure-,responsive device,`permitting the positionoflthe ]acl 3,V and hence, e.g., `thatof acircuit-breaker actuated thereby tobe, supervised by amere readingofjthgpres- 'Ihis `last arrangement is `particularly v advantageouthecase ofthe control of a-circuit-brealier hydrau 1i ack. ReferringtoFig. 3, lhaveshownthe controlldeyice zas applied to. an .electriccircuit .breaker column feornprising an upper tubularinsulator Dprovided fwith ,tivo vstationary contacts P1 and P2, alowentubularl.insulator T, .and a hydraulic jack Vamounted .between ,theeinsulatorsDand TI and having.its,pistonrodarranged-to cooperate with the .cpatacfsPl, amLPltO maken, break an electriccrcuit. fighe contactsilandYPLareconnected `into the circuit by the conductors Cl andtz,respectively.

A springlp.,is. mounted in.the, cylinder of jack-yp to urge ythe Vpistonthereof, in a direction to ybreaktheeireuit nqiheinsnaor Timitated-.with a. riiuii maman which pressure liquid may be,. del ivered, tov lone ,Said piston, t0 mOi/@ theU laitsagainst fhefatiomo f1in in a @gestion inaksithexsirrilit- Moreover, the circuit-breakingelec- The construction of the control device shown in Fig. 3 is similarto that shown in Figs. l or 2 and the same reference numerals as inFigs. l or 2 have been applied to like parts. The main iiow controlvalve 9 is connected to the continuous liquid pressure source 1 by pipe2a, to the conduit K of insulator T by pipe 2d, and to the reservoir 43by pipe 44 and the movable valve members 5 and 25 of the main flowcontrol device 9 are adapted to selectively provide a passage for liquidow from source 1 to one side of the operating piston of the circuitbreaker, or a passage for liquid flow from said piston to reservoir 43.

Such a control system operates as follows:

When a circuit-making signal is received by the circuitmakingelectro-magnet 6, the said electro-magnet is energized and lifts themovable valve member 29 of the feeding valve from its seat to permit theflow of pressure liquid from source 1 into the space of the main valve 9below the pressure responsive valve actuating piston 8 thereof. Thelatter, thus fed with pressure liquid, opens against the action of thespring .10 and the feeding valve 5 and closes the unloading valve 25.From this moment, the source 1 sends liquid under pressure into thecircuit-making jack Vp through the conduits 2a, 2b, 2c, 2d and K to movethe piston of jack Vp against the action of the return-spring Rp to setthe circuit-breaker into the circuit-making position, as shown in Figure3. The pressure in the space of main valve 9 below piston 8 ismaintained through the duct 11 and its calibrated hole so that the valvemember is in open position. In these conditions, the circuit-breaker isheld in circuitmaking position under the action of its jack Vp. Thissubsists as long as the piston 8 of the main valve 9 is not unloaded.The said unloading may be caused by the incoming into thecircuit-breaking electro-magnet 1S Iof the circuit breaking signal. Whenthus energized, the said electro-magnet takes the valve member 24 of theunloading valve oli its seat, so that piston 3 of the main valve ispermitted to move under the action of its spring 10 in a direction tobring valve member 25 into open, and valve member 5 into closedposition. The pressure line 2c, 2d and K is then unloaded and thecircuitbreaker set into circuit-breaking position by its spring Rp,which is no more opposed by any liquid pressure.

The position of the circuit-breaker is displayed on the control station,by means of the selective action of a Y pressure responsive device M1 onone of two visual indicators constituted, in the example shown, by acircuitbroken signal lamp Ld and by a circuit-made signal lamp Le. Ifthe pressure of the source 1 is insuicient to ensure in the requiredconditions, the circuit-making stroke, an interlocking device, `notshown, actuated, if desired, from the pressure responsive device M2prohibits any energizing of the circuit-making electro-magnet 15.Conversely, if the pressure of the source 1 becomes insuflicient to`maintain the circuit-breaker in circuit-making position, the saidpressure responsive device M2 automatically causes energizing of thecircuitbreaking electro-magnet 15, and hence, the operation of thecircuit-breaker into safe current interrupting position.

There is shown at Z a valve adapted to maintain in the duct throughwhich the liquid is evacuated from the circuit-making jack Vp towardsthe liquid container 43, a level ott liquid suiiiciently high to providethe required length of insulation corresponding to the voltage of thecurrent` to be cut-off.

Finally, a pump P may be provided for feeding the source 1 from theliquid container 43.

It is clear therefore, `that the invention provides a ow control devicethat is in combination with a pressure line, a tank and a continuousiluid pressure source. Thls ow control device is inserted between thesource and the pressure line and comprisesthe main body 9.

`maintains the valves 5 This body is provided with a first port meanssuch as X in each iigure, first delivery conduit pipe portions such as2a, 2b, between .the source and the port X, Figures 2 and 3 andpipeportion 2a in Figure l. The body 9 further has second port means such asY, Figure l, `and the treble orices Y', Y, and Y in Figures 2 and 3. Asecond delivery conduit provides communication between the source 1 andthis second port means. In Figure 1 this second delivery conduit iscomprised by the pipe portion 50, the bore through the body containingvalve 29, and pipe portions 49 and 41S. In Figure 2 the second deliveryconduit is pipe or duct portions 2a, 28a, the bore through the bodycontaining valve 29, pipe portion 28b, past valve 30 `and pipe portion28C, into communication with the opening Y. Each form of the inventionfurther includes means establishing communication between the pressureline and the second port means. In Figure 1 the duct or pipe portion 11,pipe portion S1 and pipe portions 51 and 48 provide for flow of fluidfrom the pressure line back to the body beneath the piston 8. InFigureZ, this communication is established by pipe portion 11a, pastvalve 31 and pipe portion 11b terminating at opening Y. The valve bodyfurther has a third port Z that is in communication. with the pressureline and an exhaust port EP. Means such as pipe portion 2c in eachfigure establish communication between the third port and the pressureline, whereas pipe 44 in Figures l and 3 and pipe 54 in Figure 2 providecommunication between the `exhaust port EP and the tank 43. In addition,there is 4a communication established between the second port means andthe tank. In Figure l this communication is by way of pipe portions 48and 51 past valve 24 when open,rthrough the bore 52 and pipe portion 54back to tank. In Figure 2 the communication is established past valve 24when open,

past the opening Y" and the further opening Y, pipe portion 56, to thelower part of pipe 54" and thence to tank. A similar arrangement isincorporated in Figure 3. In the means that establishes thecommunication between the second port means and the pressure line isprovided the permanent restricted passagel constituted by the aperturedelement 35. Within the body are movable valve means 5, 25, whichselectively provide a first passage between the rst port means X and thethird port Z and a second passage between the third port Z and theexhaust port EP. These valves are such that in the event of a pressuredrop through the second port means, that is, a pressure drop beneath thepiston 3, valve 5 will move` member, the piston S, is mounted in thebody so that when :duid enters the body through the second port means,valve 5 isopened andV valve 25 is closed. The second delivery conduithas therein a first control valve 29 controlling ow of iiuid from thesource 1 to the second port means Y, Fig. l and Y', Figures `2 and 3. Asecond control valve 24 is provided to connect the second-port meanswith the tank. In Figure l, when valve 24 is open, iiuid will flow frombeneath the piston 3 through conduit portion 51 past valve 24, ball 52through pipe 54 to tank. When valve 24 is opened in Figures 2 and 3, uidleaves the body through pipe S6, ows into pipe portion 44 (Fig. 3) and.54' (Fig. 2) thence to tank. Both of these valves are normally biased toclosed position, either hy the springs in Figure l or tluid pressure inthe other two arrangements. Manually actuated operating means areprovided to operate both of `the valves. This last-mentioned means beingeither the push buttons 6a and 15a or the button controlled solenoids 6andl 15, in the` other figures. As pointed out previously, with both ofclosed, `pressure from the line flowing past the restriction 35 entersthe body beneath the piston 8 and indeiinitely these control ortriggering valves and `25 in the position in fwhich it 7 lf'as beenpreviously brought, e.`g. the position shownY in Figures 2 and 3,wherein valve 5 is open and the Vrst passage through the body betweeninlet po-rt X and the third port vZ is open, so that pressure is exertedcontinuously from source 1 on the pressure line. This condition existsruntil valve 2.4 is opened, which occasions the pressure drop Vbeneaththe piston 8, whereupon valve i sure liquid, feeding duct means betweensaid source and said control jack and a container `at a pressure lowerthan that of said source, a hydraulic control device including a valvemeans in said feeding duct means between said source and said controljack andV controlling communication between said control jack and saidsource and between said control jack and said container respectively, aloaded hydraulic pilot jack operatively connected with said valve meansand including a piston adapted, when fed with liquid under pressure, tomove said valve means against the load to establish communicationbetween said source and said control jack, feeding means including aiirst normally closed triggering valve means operable whenopen to feedsaid pilot jack with liquid from source during a short time, unloadingmeans including a second normally closed triggering valve means operablewhen open to permit exhaust of liquid Ifrom said pilot jack, liquidconducting means downstream of said control device for placing saidpilot jack in permanent communication with said feeding duct means, formaintaining feeding of the pilot jack for an indefinite duration afterthe closing of said iirst triggering valvemeans so as to maintain thecircuit breaker in one of its circuit- Vmaking and circuit breakingpositions, and means for limiting the rate of flow through said liquidconducting means to maintain the rate of flow therethrough lower thanthe rate of ldischarge through said second triggering valve means,whereby said pilot jack means can be completely unloaded during the timeof operation of said triggering valve means so as to reset said circuitbreaker into the other one of said two positions.V

2. In a hydraulic system as claimed in claim 1 and said hydrauliccontroldevice including a valve casing, said valve means comprising two valvemembers located rwithin said casing, said valve members and said casingbeing constructed and arranged to establish the required communicationwithl said feeding duct means without any lost motion as soon as saidvalve members are actuated, and an operative mechanical connectionbetween said valve members and the piston of said pilot jack toselectively cause immediate opening of one of sai-d valve membersfollowed by closing of the other one as soon as said piston is actuated.

3. In a hydraulic system as claimed in claim 2 and each said valvemember comprising a ball valve, said valve casing having a cylindricalpassage therethrough communicating with said feeding duct means via saidcasing, a valve seat at each end of said passage for receiving said ballvalves, said operative mechanical connection comprising a piston rodfast with the piston of said pilot jack and adapted to urge that ballvalve that elements assuming s fading" valve @lass-sf, aus valve` casinghaving a cylindrical passage, and a port providing' communicationbetween said passage and the feeding duct means downstream of thecasing, through fluid ovvs into said control jack, said feediiig valveelement comprising a ball cooperable with a seat provided at one end ofsaid passage Vfor controlling municatio'n tosaid control jack, the otherof said valve elements constituting an unloading valve elementcomprising the end of a rod fastwith the piston of said pilot jack, anda second rod freelyslidable vin said passage interposed between saidvalve elements and fast with said first rod, said rods constituting the`operative mechanical connection between said valve elements.

5. In a hydraulic system as claimed in claim 1 and a spring constitutingthe load on said pilot jack and` continuously urging the piston of saidjack and said valve means toward the unloading position of the latter;

6. In a hydraulic system as claimed in claim 1 and further including anon-return valve interposed in said feeding duct means between saidsource and said pilot jack.

7. In a hydraulic system as claimed in claim 1 also including anon-return valve in said liquid conducting means between the meanslimiting the return of flow therethrough and said pilot jack.

8. In a hydraulic system as claimed in claim 1 and including anon-return valve interposed in said feeding duct means `between saidsource and said pilot jack and another non-return valve interposed insaid Vliquid coriducting means between the means limiting the Howtherethrough and said pilot jack.

9. In a hydraulic system as claimed in claim a push button operativelyconnected with at least one orf said normally closed triggering valvemeans so as to permit opening thereof during a short time.

10. In a hydraulic system as claimed in claim 1 and an electro-magnetoperatively associated with at least one of said 'normally closedtriggering valve means and operable to open the same during a shorttime.

ll. In a hydraulic control system as claimed in claini l and alsoincluding means operatively associated with said second triggering valvemeans and operable responsive to pressure in said source to actuate saidsecond triggering valve means in response to a predetermined pressure insaid source.

12. The combination with a pressure line, a tank and a continuous uidpressure source for delivering uid under pressure to said line, of aflow controlV device to be inserted between said source and saidpressure line and comprising a body having a first port means, a Yfirstdelivery conduit providing communication between said source and saidfirst port means, said body further having second port means, a seconddeliveryy conduit providing communication between said source and saidsecond port means, means establishing communication between saidpressure line and said second port means, a thirdA port communicatingwith said pressure line and an exhaust port, means establishingcommunication between said exhaust port and said tank, meansestablishing communication between said second port means and said tank,means providing a permanentv restricted passage in the meansestablishing communication between said second port means and' saidpressure line, movable valve means arranged in said bodyV to selectivelyprovide a first passage between said rst port means and said thirdl huidpressure entering saidvbody throughv said second port meansto therebyclose said second passage and to open said first passage, a firstcontrol valve in said second delivery conduit for controlling the flowof uid from said source to said second port means, a second controlyValve adapted to connect said second port means with said tank, saidrst and second control valves being normally biased to closed position,and manually actuated operating means adapted to operate each of saidrst and second control valves to open position, whereby with both saidcontrol valves closed pressure through said restricted passageindefinitely maintains said movable valve means in a position topros/ide a passage between said irst port means and said third port toprovide communication between said source and said pressure line 10until operation of said second control valve means to open position.

References Cited in the file of this patent UNITED STATES PATENTS1,947,191 Davis et al. Feb. 13, 1934 2,231,708 Dutling Feb. 11, 19412,308,261 Bartlett et al. Jan. 12, 1943 2,314,398 Hoch Mar. 23, 19,432,430,128 Levstrup Nov. 4, 1947 2,464,237 Kelle Mar. 15, 1949 2,473,687Kershaw June 21, 1949 2,491,112 Janssen Dec. 13, 1949 2,514,747 DanielsJuly 11, 1950

